/*
 * project.c - Load and save solidify project descriptions
 *
 * Written 2010 by Werner Almesberger
 * Copyright 2010 by Werner Almesberger
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */


#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <math.h>

#include "util.h"
#include "face.h"
#include "solid.h"
#include "project.h"


static struct project *make_project(const char *name,
    const char *top, const char *bottom, double dist_mm)
{
	struct project *prj;

	prj = alloc_type(struct project);
	prj->name = stralloc(name);
	prj->top = stralloc(top);
	prj->bottom = stralloc(bottom);
	prj->s.a = read_face(top);
	prj->s.b = read_face(bottom);

	if (prj->s.a->x_step != prj->s.a->x_step ||
	    prj->s.a->y_step != prj->s.a->y_step ||
	    prj->s.a->z_step != prj->s.a->z_step) {
		fprintf(stderr, "both faces must have the same resolution\n");
		exit(1);
        }

	prj->s.dist = dist_mm/prj->s.a->z_step;
	return prj;
}


struct project *new_project(const char *name,
    const char *top, const char *bottom, double dist_mm)
{
	FILE *file;

	file = fopen(name, "r");
	if (file) {
		fprintf(stderr, "%s: already exists\n", name);
		exit(1);
	}
	return make_project(name, top, bottom, dist_mm);
}


static void read_face_data(FILE *file, struct face *f)
{
	float v;

	if (fscanf(file, "%f", &v) != 1)
		return;
	f->z_ref = v/f->z_step;

	if (fscanf(file, "%f", &v) != 1)
		return;
	f->fx = tan(v/180*M_PI);

	if (fscanf(file, "%f", &v) != 1)
		return;
	f->fy = tan(v/180*M_PI);

	if (fscanf(file, "%f", &v) != 1)
		return;
	v = v/180*M_PI;
	f->m.a[0][0] = cos(v);
	f->m.a[0][1] = -sin(v);
	f->m.a[1][0] = sin(v);
	f->m.a[1][1] = cos(v);

	if (fscanf(file, "%f", &v) != 1)
		return;
	f->m.b[0] = v/f->x_step;
	
	if (fscanf(file, "%f", &v) != 1)
		return;
	f->m.b[1] = v/f->y_step;
}


static void read_optional(FILE *file, struct project *prj)
{
	float v;

	if (fscanf(file, "%f", &v) != 1)
		return;
	prj->s.dist = v/prj->s.a->z_step;

	read_face_data(file, prj->s.a);
	read_face_data(file, prj->s.b);
}


struct project *load_project(const char *name)
{
	FILE *file;
	char top[1000], bottom[1000]; /* @@@ enough */
	struct project *prj;

	file = fopen(name, "r");
	if (!file) {
		perror(name);
		exit(1);
	}

	if (!fgets(top, sizeof(top), file)) {
		fprintf(stderr, "%s: can't read name of top face\n", name);
		exit(1);
	}
	if (strchr(top, '\n'))
		*strchr(top, '\n') = 0;

	if (!fgets(bottom, sizeof(bottom), file)) {
		fprintf(stderr, "%s: can't read name of bottom face\n",
		    bottom);
		exit(1);
	}
	if (strchr(bottom, '\n'))
		*strchr(bottom, '\n') = 0;

	prj = make_project(name, top, bottom, 0);

	read_optional(file, prj);

	return prj;
}


static void save_face_data(FILE *file, const char *name, const struct face *f)
{
	double a;

	a = asin(-f->m.a[0][1])/M_PI*180;
	if (f->m.a[0][0] < 0)
		a = 180-a;
	if (fprintf(file, "%g %g %g\n%g %g %g\n",
	    f->z_ref*f->z_step,
	    atan(f->fx)/M_PI*180, atan(f->fy)/M_PI*180,
	    a, f->m.b[0]*f->x_step, f->m.b[1]*f->y_step) < 0) {
		perror(name);
		exit(1);
	}
}


void save_project(const struct project *prj)
{
	char tmp[1000]; /* @@@ enough */
	FILE *file;

	sprintf(tmp, "%s~", prj->name);
	file = fopen(tmp, "w");
	if (!file) {
		perror(tmp);
		exit(1);
	}
	if (fprintf(file,
	    "%s\n%s\n%g\n", prj->top, prj->bottom,
	    prj->s.dist*prj->s.a->z_step) < 0) {
		perror(tmp);
		exit(1);
	}
	save_face_data(file, tmp, prj->s.a);
	save_face_data(file, tmp, prj->s.b);
	if (fclose(file) < 0) {
		perror(tmp);
		exit(1);
	}

	if (rename(tmp, prj->name) < 0) {
		fprintf(stderr, "rename %s to %s: %s\n", tmp, prj->name,
		    strerror(errno));
		exit(1);
	}
}